The military have many different types of projectiles of tank and artillery rounds and new ones are being developed constantly. For each operating projectile, an identically shaped training projectile is required for use in training personnel who will use the real or armed projectile. Usually, the design of a training projectile is relatively straightforward, particularly when the projectile is of small diameter. However, a newly developed projectile has a relatively large diameter and the design of a training version thereof which is stable in flight, light in weight and traverses a suitable distance is not straightforward.